title: Osteosarcoma arising in heterotopic ossification of dermatomyositis: case report and review of the literature.
abstract: A patient with dermatomyositis developed malignant transformation of the benign interfascial heterotopic bone. This patient had classic childhood dermatomyositis at the age of 3 years, and the disease was arrested after a one-year course of corticosteroid therapy. Extensive subcutaneous calcinosis cutis and deep interfascial calcinosis were the residua of the disease. Twenty-eight years later, the patient developed a high-grade osteosarcoma within the benign intermuscular heterotopic calcification and ossification that had been previously documented at the age of 8 years by a roentgenogram and at the age of 16 years by biopsy. This case represents the first report of the association of osteosarcoma and dermatomyositis, and possibly the first well-documented case of malignant transformation of benign heterotopic bone.
mesh_terms: D000328:Adult; D001706:Biopsy; D002114:Calcinosis / Q000150:complications / Q000000981:diagnostic imaging; D003882:Dermatomyositis / Q000150:complications* / Q000000981:diagnostic imaging; D005266:Femoral Neoplasms / Q000000981:diagnostic imaging / Q000209:etiology*; D006801:Humans; D008297:Male; D009999:Ossification, Heterotopic / Q000150:complications* / Q000000981:diagnostic imaging; D012516:Osteosarcoma / Q000000981:diagnostic imaging / Q000209:etiology*; D011859:Radiography